In situ observation of ZnO nanowire growth on zinc film in environmentalscanning electron microscope

摘要

In situ uniform growth of ZnO nanowires was realized and monitored at real time by heating zincfilm in an environmental scanning electron microscope. Better controllability and repeatability wereobtained by using zinc film as source material compared to traditionally used zinc powder.Morphology of the as-grown ZnO nanowires was found to depend on both the growth temperatureand holding time. Low temperature (500 °C) and short growth time (-20 min) favorone-dimensional nanowire growth, whereas longer holding time (>40 min) or higher temperature(700 °C) lead to nanosheet growth. The results suggest that the zinc vapor partial pressure is vitalin determining the final morphology. These results help to give more insights into the mechanism ofZnO nanowire synthesis.